Regresssion from bd8a7edbd2.

When the toolbar buttons are overridden with URL parameters, our computed set of
buttons will be wrong. Thus, compute it every time and check for the
differences.

Note that in the usual (vertical) setup, the "toolbar" is just the hide button.

* fix(thumbnail): Optimize status bar moderator icon

Moved all moderator functionality to react to optimize the number of
status bar updates.

* fix(RemoteVideoMenuTriggerButton): Use nullish coalescing

Co-Authored-By: Saúl Ibarra Corretgé <saghul@jitsi.org>

* ref(StatusBar): rename to StatusIndicators

* fix(RemoteVideoMenu): isModerator value.

* fix(notification): mobile.

Co-authored-by: Saúl Ibarra Corretgé <s@saghul.net>

* ref(Filmstrip): Optimize resizes.

* fix(thumbnails): resize.

* fix(thumbnails): Issue with height 0, width 0.

* doc(Filmstrip): Improve JSDoc.

🔥🔥🔥

For the most part the changes are taking the "static propTypes" declaration off
of components and declaring them as Flow types. Sometimes to support flow some
method signatures had to be added. There are some exceptions in which more had
to be done to tame the beast:
- AbstractVideoTrack: put in additional truthy checks for videoTrack.
- Video: add truthy checks for the _videoElement ref.
- shouldRenderVideoTrack function: Some component could pass null for the
  videoTrack argument and Flow wanted that called out explicitly.
- DisplayName: Add a truthy check for the input ref before acting on it.
- NumbersList: Move array checks inline for Flow to comprehend array methods
  could be called. Add type checks in the Object.entries loop as the value is
  assumed to be a mixed type by Flow.
- AbstractToolbarButton: add additional truthy check for passed in type.

* feat(tile-view): initial implementation for tile view

- Modify the classname on the app root so layout can adjust
  depending on the desired layout mode--vertical filmstrip,
  horizontal filmstrip, and tile view.
- Create a button for toggling tile view.
- Add a StateListenerRegistry to automatically update the
  selected participant and max receiver frame height on tile
  view toggle.
- Rezise thumbnails when switching in and out of tile view.
- Move the local video when switching in and out of tile view.
- Update reactified pieces of thumbnails when switching in and
  out of tile view.
- Cap the max receiver video quality in tile view based on tile
  size.
- Use CSS to hide UI components that should not display in tile
  view.
- Signal follow me changes.

* change local video id for tests

* change approach: leverage more css

* squash: fix some formatting

* squash: prevent pinning, hide pin border in tile view

* squash: change logic for maxReceiverQuality due to sidestepping resizing logic

* squash: fix typo, columns configurable, remove unused constants

* squash: resize with js again

* squash: use yana's math for calculating tile size

* ref(filmstrip): create an empty container for local filmstrip move

This might be necessary for tile view. To support making the
local video display at the end of remote videos while in tile
view, but separateed from scrollable remote videos, moving
the local video might be necessary. By creating an empty
container, there is a target for local video to move to.

* squash: rename id

Very likely I broke something subtle and I'm prepared to fix it.

Contributing all buttons in one place goes against the designs that we
set out at the beginning of the project's rewrite and that multiple of
us have been following since then.

Prepare for React 16.

* feat(small-video): use InlineDialog for stats and remote menu

- Remove JitsiPopover and use InlineDialog instead.
- Bring the remote menu icon into react.
- Make vertical filmstrip position:fixed so popper (AtlasKit
  dependency) sets InlineDialogs and eventually tooltips to
  position:fixed.

* ref(remote-menu): hook KickButton to redux

* ref(remote-menu): hook MuteButton to redux

* modify padding, toggle dialogs

* pixel push margins to align dialogs, adjust padding of dialogs

* add comment about margin for dialog, add file I forgot

* modify indicator markup so the icon can be moved down while trigger stays at top of toolbar

* feat(indicators): move the "top toolbar" indicators to react

* wrap baseindicator

Move display of audio muted, video muted, and moderator icons,
which make up the elements of the small video toolbar, into React
Components.